Process of preparing a lubricating oil



Patented June 8, 1926.

UNITED STATES WIR'I D, RIAL, OF WILMINGTON, CALIFORNIA.

PROCESS OF PREPARING A LUBRICATING OIL.

2N0 Drawing.

My invention relates to a. lubricating, oil and the manner of preparing the same, the object of the invention being to provide an improved process of preparing a mineral oil lubricating compound.

The invention consists in mixing with a petroleum hydrocarbon a fixed vegetable oil of the fatty acid series, among which is included for purposes of this disclosure castor oil, but to which I do not specifically limit myself, though I have chosen to dwell on it as the oil of the compound herein described. Other oils of this group and of the group of saponifiable fats are probably adaptable for increasing the lubricating qualities of a mineral oil, but I have preferred the castor oil because of them all it is the most viscous. The high viscosity of this vegetable oil renders it resistant to solution in mineral oils, at least of the heavier series, and in order to make it susceptible to assimilation by the mineral oil, the vegetable oil must first be treated.

Attempts have been made to mix vegetable oils and saponifiable fats such as castor oil, with petroleum hydrocarbons, but so far as I am aware, no commercially successful and economical method has been de vised to bring about a blending of the castor oil and mineral oil in order to form a mineral oil lubricating compound. The methods and uses that are followed in a few instances for compounding saponifiable fats with mineral oil for lubricating purposes are too costly to make their adoption and practice general in the art and field of lubrication.

I have discovered that the lubricating qualities of mineral oil are bettered to a considerable extent by mixing with such oil a quantity of castor oil. But owing to the fact that castor oil, as such, is very viscous, it is not suitable for lubricating purposes by itself, and is difiicultly soluble only to a small extent in heavier hydrocarbons, I first treat the castor oil to render it miscible with mineral oil. For this purpose I subject the castor oil to the action of a cresol, such as a cresylic acid, which acts upon the castor oil to make it assimilable by the mineral oil and, by increasing the capillarity of the castor oil, augments, to a marked degree, the ability of the castor oil to penetrate. Gresylic acid is ideally adapted for this purpose, but anthracenic and naphthenic oils, may answer the purpose, as may Application filed November 2, 1925. Serial No. 66,387.

also some of the intermediates of the coal tar group of oils.

I find that cresylic acid admixed with a vegetable oil, especially castor oil in proportions required, and this mixture admixed or blended with a preferably non-viscous mineral oil, produces an oil of excellent lubrieating quality. While I have found that the proportions of five per centum of castor oil or other oil and not exceeding two per centum of cresylic acid yield satisfactory results, I do not limit myself to these proportions which may be changed as conditions require and sustain any proportionate relation to the mineral oil with which it is to be compounded, since by my method of compounding, the vegetable oil is wholly assimilated by the mineral oil.

I have found that where castor or other vegetable oil is first treated with cresylic acid, its assimilation by the mineral oil is nearly perfect and the mineral oil thus rendered ideally fit as a lubricating oil. In this condition and by this manner of compounding, the oils do not stratify. The

lubricating oil as thus compounded is highly penetrative and absorptive of heat.

It will be understood herein that mineral oil as referred to, does not include those lighter fractions of hydrocarbons which act as solvents for the vegetable oil. It includes particularly those hydrocarbons which are suitable for lubricating compounds, as lubricating stocks and distillates. A specific example of lubricating oil compounded according to my invention would be as follows: 5% castor oil, 5% oil of mirbane, 1% cresylic acid, 89% very light lubricating oil.

In practice .I have found that cresylic acid which I prefer to use, diffuses a disagreeable odor and while it is not necessary to deodorize the compound, I find that the pungently oflensive odor of the cresol may be'minimized or wholly neutralized by the use of deodorants. Any suitable deodorant may be employed for this purpose, but essential oils are preferable, and may include such as mirbane, eucalyptus, acacia and others. Used in proportion of say five per centum, the cresylic acid is entirely deodorized.

What I claim, is:

1. The process of preparing a lubricating oil which consists in treating a fixed vegetable oil with a carbocyclic acid capable of increasing the capillarity of the caster oil,

and then mixing the vegetable oil thus treated with mineral oil.

2. The process of preparing a lubricating oil whichconsists in treating a fixed vegetor oil with cresylic acid, and then blending the castor oil thus treated, with non-viscous mineral oil.

4. The process of preparing a compound lubricating oil from mineral oil consisting in admixing castor oil with cresylic acid in the approximate proportion of five to one and then adding such mixture to a nonviscous mineral oil to be compounded.

In testimony whereof I have set my hand.

WIRT D. RIAL. 

